1. Field of the Invention
The present invention relates to a vehicle motion control apparatus.
2. Description of the Related Art
JP 2003-170822A (see FIG. 6) discloses, for a driving force distribution device that distributes the driving force to the right and left wheels in order to control a vehicle yaw moment, a technology of performing yaw rate feedback control and slip angle feedback control on the driving force distribution amount based on an accelerator open quantity, an engine rotation speed, a vehicle speed, a front-wheel turning angle, a lateral direction acceleration, a yaw rate, and vehicle-body sideslip angle (may also be called a vehicle slip angle), etc.
Also, there are known a control device of controlling respective driving forces of the right and left wheels based on a vehicle slip angle in order to control a yaw moment, and a technology of correcting/controlling the front-wheel turning angle based on a vehicle slip angle.
JP 09-99826A (see FIGS. 2 to 7 and paragraphs from 0077 to 0081) discloses a control device which calculates a target yaw moment from the slip angle of a rear wheel axis and the slip-angle velocity thereof in order to control respective driving forces of the right and left wheels, thereby controlling the yaw moment of a vehicle.
US 2009/0118905A1) discloses, in FIGS. 1 and 2, a recent vehicle motion control apparatus with improvements of the turning characteristic of allowing a vehicle to turn as a driver intends, prevents the vehicle from spinning, and suppresses a false operation and an excessive control. Such a vehicle motion control apparatus includes a feedback distributing/calculating means which compensatingly calculates a virtual external force to be fed back to a motional model of the vehicle based on a deviation between a vehicle first model state quantity (corresponding to a “reference attitude-state quantity” of the present invention) based on the motional model of the vehicle and a vehicle first actual state quantity (corresponding to a “actual attitude-state quantity” of the present invention), and which calculates a yaw moment, etc., to be fed back to the driving amount of an actuator that generates a vehicular motion.
According to the vehicle motion control apparatus disclosed in US 2009/0118905 A1, the disclosure of which is herein incorporated by reference in its entirety, when a signal output by a sensor that detects a vehicle operated state quantity by a driver and the motional state quantity of the vehicle is abnormal, and when it is expected that an actual-state-quantity determining means (corresponding to an “actual attitude state determining unit” of the present invention) which detects or estimates the first actual state quantity of the vehicle based on a signal output by the sensor calculates an abnormal result, if a virtual external force calculated based on these conditions is directly fed back to the motional model of the vehicle, a difference between the first model state quantity of the vehicle and the first actual state quantity becomes large, so that the driver may feel strangeness.